Anaerobic digestion

Anaerobic digestion (AD) plants degradeTo break down organic substances by living organisms, also referred to as biodegradation. organic material using micro-organismsThese are tiny organisms that comprise either a single cell, cell clusters or multicellular relatively complex organisms. Micro organisms are very diverse and include bacteria, fungi, and algae, and act as decomposers, breaking down dead or decaying organisms. in the absence of oxygen to produce biogas, a mixture of methane (circa 60%), carbon dioxide (circa 40%) and trace amounts of other gases.

To date, use of ADThis is the process where plant and animal material is converted into useful products by micro-organisms in the absence of air. Biomass is put inside sealed tanks and naturally occurring micro-organisms digest it, releasing methane that can be used to provide clean renewable energy. for methane production has generally been limited by high construction costs and a lack of technical expertise to operate plants. However, increasingly stringent anti-landfill legislation is expected to lead to greater use of AD to deal with organic waste, thereby reducing the amount of waste sent to landfill.

Apart from the capital cost of building a plant, biogas produced by AD has several potential advantages over landfill gas as follows:

AD gas is less complex and has a higher methane content at ~60% (~50% for landfill gas).

Front-end revenue can be generated through ‘gate fees’ for receiving waste.

The process allows operations to be strategically located close to the origin of waste arising and demand for product.

​In the Philippines, where Gazasia’s initial projects are located, the average waste produced per capita typically ranges between 0.4 and 0.5 kgs per day, of which the organic content is 40–50%. This waste is currently sent to dumpsites and/or landfill. Waste is also generated by food manufacturers, supermarkets, plantations and wastewater companies, while agricultural processes such as rice production and fermentation are large producers of methane.